This invention relates to a device and method for storing cooked food portions at elevated temperatures and more particularly to a staging device for holding previously cooked food portions at elevated temperatures.
Quick service restaurants face a number of conflicting factors when striving to provide fast, palatable and safe food. First, the customers expect to receive their food quickly, with a minimum of delay and with predictable and constant high quality. Moreover, the rate of customer demand varies over time, with some periods, such as lunch and dinner times, having extremely high rates of customer demand. However, the kitchens of many quick service restaurants are of limited size and/or production capacity and thus necessarily have a limited number of food cooking devices.
Typical food products that are of most interest include sandwiches that are composed of a bun or other bakery cooked bread product and a sandwich filling that is cooked at the quick service restaurant. Typical sandwich fillings include hamburger patties, breaded fish fillets, Canadian bacon, pork sausage, eggs and breaded chicken patties, for example, as well as other products, such as chicken nuggets, biscuits, muffins and hotcakes. Consequently, the cooked food supply capacity of the restaurant is limited by the size and number of food cooking devices located at the restaurant.
To meet the competing factors of quick service and consistent high quality, it is advantageous for quick service restaurants to frequently cook a number of individual food sandwich filling portions which are then almost immediately incorporated into individual sandwiches and then wrapped and held ready in advance of actual customer orders in an open storage bin for a relatively short predetermined period of time. To insure constant high quality, if the items are not sold prior to the expiration of that time, the sandwiches are destroyed. Holding the previously cooked, prepared and wrapped sandwiches incorporating the previously cooked sandwich fillings is thus of limited utility.
Since some quick service restaurants sell very large quantities of food, even a small increase in the efficiency of handling cooked sandwich fillings and other food would be desirable.
A need exists for a device and method that acts as a buffer between the relatively fixed and limited capacity of the sandwich filling cooking step and the highly variable completed sandwich demand without any significant adverse impact on sandwich quality or food safety. In addition, a need also exists for a food staging device that promotes efficient food handling and use of space within the kitchen of the quick service restaurant.
In accordance with the present invention, an improved food staging device and method for holding previously cooked food items at elevated temperatures is provided.
The device is particularly adapted for storing over extended periods of time cooked sandwich fillings such as hamburger patties, fish fillets, Canadian bacon, pork sausage, eggs, chicken patties, chicken fillets, as well as other types of food, including biscuits, muffins and hotcakes. When used in combination with trays specifically configured for use in the staging device, the appearance, taste, and texture of the previously cooked food items is maintained over extended storage periods (such as about up to two hours or more depending on the type of food) without risk of bacterial contamination. In addition, the device provides a measure of quality control by insuring xe2x80x9cdoneness,xe2x80x9d which is defined as achieving the required health code temperature and coloration.
In accordance with another aspect of the invention, a method is provided for storing previously cooked food, that is especially suited for a plurality of individual portion sandwich fillings, over extended periods of time without any significant detrimental effect on the quality of the food, including the appearance, taste and texture and without risk of bacterial contamination.
In one aspect, the food staging device in accordance with the invention includes a cabinet containing a plurality of discrete compartments, each bounded by an upper heated compartment surface and a lower heated compartment surface. The upper and lower compartment surfaces are constructed from a material having a high thermal conductivity, preferably from anodized aluminum. The previously cooked food portions are held within the compartments until the food portions are sold or otherwise disposed of. The air currents throughout the cabinet, if any, are limited because each of the compartments is segregated from other compartments and has solid upper and lower surfaces as well as closed sidewalls and limited access doors, the combination of which limits air flow in the compartments. In addition, air currents within the compartments are limited because both the lower and upper surfaces of the compartments are heated, thereby minimizing regions of thermal gradients within the compartments.
The device also includes at least one inlet door on one side of the device for inserting the food portions into the compartments and one complementary outlet door on the opposite side of the device for removing therethrough food portions contained in the compartments. This pass-through configuration of the doors promotes an efficient use of space in the kitchen containing the device because, for example, the device can be positioned intermediate the food cooking area and the cooked food assembly area, thereby providing cooking and assembly restaurant personnel separate access to the device. One inlet and corresponding outlet door may be provided to service one, two or more compartments.
In accordance with another aspect of the invention, the device may include a plurality of opposed corresponding inlet and outlet doors such that each of the compartments has its own inlet and outlet door. In addition, the inlet and outlet doors preferably are vertically spaced apart from each other by a distance approximately equal to the thickness of the doors to enable the doors to open by swinging in a generally upward direction, without any further structure enclosing the cabinet interior in the area between adjacent doors from the exterior. Thus, there is provided a relatively narrow, elongated slot opening permitting limited airflow between the compartment of the device and the atmosphere. Typically, the slot height should be no more than about 0.25 inches. Using a separate inlet and outlet door for each compartment further limits air transfer between the interior of the device and the atmosphere, thereby limiting vapor transfer from the cooked food articles contained therein and further protecting the appearance, taste, and texture of the food portions. The inlet and outlet doors preferably are attached to the cabinet by pins located at the upper opposed edges of the doors, enabling the doors to open by swinging in a generally upward direction. If desired, no stops are provided for holding the doors open. Consequently, the doors automatically close by their own weight, thereby further minimizing air transfer and promoting a relatively constant temperature within the compartments. Alternatively, a stop may be provided for each door as desired to hold it in an open position.
In another aspect, the food staging device in accordance with the invention includes a cabinet containing a plurality of discrete compartments, each bounded by an upper heated compartment surface and a lower heated compartment surface. However, no inlet or outlet doors are provided to the compartments, leaving open, unobstructed inlet and outlet areas. The upper and lower compartment surfaces are constructed from a material having a high thermal conductivity, preferably from anodized aluminum. Air currents throughout the cabinet, if any, are limited because each of the compartments is segregated from other compartments and has solid upper and lower surfaces as well as closed sidewalls and the trays configured for use in the compartments are sized to allow a minimum and controlled air gap between the top of the tray and the upper surface of the compartment. One inlet area is provided on one side of the device for inserting the food portions into the compartments and one complementary outlet area is provided on the opposite side of the device for removing therethrough food portions contained in the compartments. Generally, one inlet area and a corresponding outlet area are provided for access to each compartment. The unobstructed inlet and outlet areas provide cooking and assembly restaurant personnel quick access to the device for inserting and removing cooked food. Using a separate inlet and outlet area for each compartment limits air transfer between the interior of the device and the atmosphere, thereby limiting vapor transfer from the cooked food articles contained therein and further protecting the appearance, taste, and texture of the food portions.
In accordance with another aspect of the invention, the device includes a plurality of trays for containing the food portions. One type of tray includes a sidewall having an upper edge and a lower edge, a closed bottom attached to the lower edge, and an open top defined by the upper edge. The trays have a height such that the top edges of the trays are a predetermined vertical distance, generally in the range of from 0 to 0.090 inches and most preferably about 0.060 inches, from the upper heated compartment surface when the trays are inserted into the compartments, thereby creating a controlled, almost sealed section between the tray and the compartment. The preferred gap for biscuits and hotcakes is about 0.125 inches. A typical tray height is in the range of from about 2 inches to about 2.5 inches. By limiting the space between the top edges of the trays and the upper compartment surface, and plate surface temperature, evaporation of liquid from the cooked food portions is minimized, thereby maintaining the appearance, taste, and texture of the cooked food held in the device over extended storage periods such as up to about two hours. In addition, the trays can be configured such that the length of the trays is less than but approximately equal to the depth of the compartments, thereby enabling easy removal of the trays through the outlet area of the compartment.
Typical storage temperatures are in the range of from about 145-210xc2x0 F. and preferably about 155xc2x0 F. for biscuits, hamburger patties, grilled chicken, eggs, Canadian bacon, pork sausage, hotcakes and muffins, about 200xc2x0 F. for breaded chicken nuggets, breaded chicken fillets and breaded fish fillets. Trays with solid bottoms and raised sides are preferred for unbreaded meat and other food products such as hamburger patties, grilled chicken, eggs, Canadian bacon, pork sausage, biscuits, muffins and hotcakes. Flat trays with a mesh or wire grid with low sides are preferred for fried breaded products including breaded chicken nuggets, breaded chicken and fish fillets.
In accordance with yet another aspect of the invention, each of the compartments includes an upper electric resistance heating element for heating the upper compartment surface and a lower electric resistance heating element for heating the lower compartment surface. Additionally, temperature sensors are provided on the upper and lower compartment surfaces for monitoring the temperature of each surface. The temperatures generated by the heating elements therefore can be individually monitored and controlled by appropriate control circuitry. Consequently, the compartment temperatures can be separately controlled thus providing different holding temperatures in different compartments. As a result, the device can be used to simultaneously hold previously cooked food items at two or more temperatures, therefore eliminating the need for separate staging devices and further promoting an efficient use of space within the kitchen containing the staging device.
In accordance with another aspect of the invention, a method of storing previously cooked food products is provided. In accordance with this method, the previously cooked food products (such as individual portion sandwich fillings) are stored in a device that is composed of at least one compartment for holding the food portions, with the compartment bounded by upper and lower heated compartment surfaces. A cabinet defines an enclosed volume for housing the compartment therein, the cabinet including at least one area for inserting and removing the food portions from the compartment, where the compartment has a predetermined compartment height and width. The method includes placing the previously cooked sandwich fillings in at least one tray having a solid bottom and upwardly extending tray walls resulting in a tray height that is about 0 to 0.090 inches less than the compartment height. Thereafter, the tray containing the cooked sandwich fillings is placed in the heated compartment with the heated compartment surfaces having a temperature in the range of from about 145xc2x0 F. to less than the boiling point of water. A gap is achieved between the top of the tray and the upper heated compartment surface between about 0 and 0.090 inches for restricting and controlling water vapor evaporating from the sandwich fillings contained in the tray. Thereafter, the inlet door is closed, if there is one, and the sandwich fillings in the tray are stored for a desired period of time.
Preferably, in accordance with the foregoing method, the cooked sandwich fillings stored in the tray fill at least about 5% and most preferably at least 50% of the tray volume.